What on earth is this latest strike about? For once, the whole line is
suspended, and a total of four days travel will be disrupted. It's
supposedly not about pay, or the usual claims of victimisation of union
activists.

https://www.standard.co.uk/news/transport/piccadilly-line-strike-passengers-battle-panic-attacks-and-endure-dangerous-overcrowding-in-rush-a3947231.html